摘要:We study the coupled Choquard type system with lower critical exponents $$ \textstyle\begin{cases} -\Delta u \lambda _{1}(x)u=\mu _{1}(I_{\alpha }* \vert u \vert ^{ \frac{N \alpha }{N}}) \vert u \vert ^{\frac{\alpha }{N}-1}u \beta (I_{\alpha }* \vert v \vert ^{ \frac{N \alpha }{N}}) \vert u \vert ^{\frac{\alpha }{N}-1}u,\quad x\in {\mathbb{R}}^{N}, \\ -\Delta v \lambda _{2}(x)v=\mu _{2}(I_{\alpha }* \vert v \vert ^{ \frac{N \alpha }{N}}) \vert v \vert ^{\frac{\alpha }{N}-1}v \beta (I_{\alpha }* \vert u \vert ^{ \frac{N \alpha }{N}}) \vert v \vert ^{\frac{\alpha }{N}-1}v,\quad x\in {\mathbb{R}}^{N}, \\ u, v\in H^{1}({\mathbb{R}}^{N}), \end{cases} $$ where $N\ge 3$ , $\mu _{1}, \mu _{2}, \beta >0$ , and $\lambda _{1}(x)$ , $\lambda _{2}(x)$ are nonnegative functions. The existence of at least one positive ground state of this system is proved under certain assumptions on $\lambda _{1}$ , $\lambda _{2}$ .
关键词:Choquard system ; Lower critical exponent ; Positive ground state